Prevent loop request on database to allocate a permalink

[albandiguer]

See https://gist.github.com/44ea6f4e523265b15488

This is not a NavigationItem concern Move it the Permalink module or create one appropriated class, remove the loop over db query

while .... do end

makes a O(n) instead of O(const)

[albandiguer]

Done in commit 19171d39b876885594e12e6ce0ed6923ad84cc2c